import argparse
import datetime
import json
import logging
import math
import os
from itertools import product

import pandas as pd
import torch

from grouped_gemm.kernels.tuning import (
    KernelConfigBackward_dW,
    KernelConfigBackward_dX,
    KernelConfigForward,
    KernelResult,
)

SEED = 42


def create_merged_results(
    df: pd.DataFrame, mode: str, seqlen: int, dtype: torch.dtype, autotune: bool
):
    kernel_result_cols = df.columns.to_list()
    test_config_dict = {
        "mode": mode,
        "seqlen": seqlen,
        "dtype": dtype,
        "autotune": autotune,
    }
    test_config_cols = list(test_config_dict.keys())
    for col in test_config_cols:
        df[col] = test_config_dict[col]
    # Reorder columns so that test config cols are first
    df = df[test_config_cols + kernel_result_cols]
    return df


def post_process_results(
    results: list[KernelResult], mode: str, seqlen: int, dtype: torch.dtype, autotune: bool
):
    df = KernelResult.to_dataframe(results, sort_by = "speedup")
    df = create_merged_results(df, mode, seqlen, dtype, autotune)
    return df


def save_results(
    df: pd.DataFrame, results_dir: str, mode: str, seqlen: int, dtype: torch.dtype, autotune: bool
):
    dt = datetime.datetime.now().strftime("%Y%m%d_%H%M")
    save_dir = f"{results_dir}/{mode}"
    save_path = f"{save_dir}/{dt}_{seqlen}_{str(dtype).split('.')[-1]}.csv"
    if not os.path.exists(save_dir):
        os.makedirs(save_dir)
    print(f"Saving results to {save_path}")
    df.to_csv(save_path, index = False)


def create_kernel_configs(args: argparse.Namespace, permute_x: bool, permute_y: bool):
    block_m_range = power_of_two_range(args.BLOCK_SIZE_M[0], args.BLOCK_SIZE_M[1])
    block_n_range = power_of_two_range(args.BLOCK_SIZE_N[0], args.BLOCK_SIZE_N[1])
    block_k_range = power_of_two_range(args.BLOCK_SIZE_K[0], args.BLOCK_SIZE_K[1])
    num_warps_range = multiples_of_range(args.num_warps[0], args.num_warps[1], step = 2)
    num_stages_range = multiples_of_range(args.num_stages[0], args.num_stages[1], step = 1)

    mode = args.mode
    kernel_configs = []
    for (
        block_m,
        block_n,
        block_k,
        num_warps,
        num_stages,
        tma_load_a,
        tma_load_b,
    ) in product(
        block_m_range,
        block_n_range,
        block_k_range,
        num_warps_range,
        num_stages_range,
        [True, False],
        [True, False],
    ):
        if mode == "forward":
            kernel_config = KernelConfigForward(
                BLOCK_SIZE_M = block_m,
                BLOCK_SIZE_N = block_n,
                BLOCK_SIZE_K = block_k,
                num_warps = num_warps,
                num_stages = num_stages,
                use_tma_load_w = tma_load_a,
                use_tma_load_x = tma_load_b,
                permute_x = permute_x,
                permute_y = permute_y,
            )
        elif mode == "dW":
            kernel_config = KernelConfigBackward_dW(
                BLOCK_SIZE_M = block_m,
                BLOCK_SIZE_N = block_n,
                BLOCK_SIZE_K = block_k,
                num_warps = num_warps,
                num_stages = num_stages,
                use_tma_load_dy = tma_load_a,
                use_tma_load_x = tma_load_b,
                permute_x = permute_x,
                permute_y = permute_y,
            )
        elif mode == "dX":
            kernel_config = KernelConfigBackward_dX(
                BLOCK_SIZE_M = block_m,
                BLOCK_SIZE_N = block_n,
                BLOCK_SIZE_K = block_k,
                num_warps = num_warps,
                num_stages = num_stages,
                use_tma_load_dy = tma_load_a,
                use_tma_load_w = tma_load_b,
                permute_x = permute_x,
                permute_y = permute_y,
            )
        else:
            raise ValueError(f"Invalid mode: {mode}")
        kernel_configs.append(kernel_config)

    logging.info(f"Pruning {len(kernel_configs)} kernel configs")

    pruned_configs = []
    for config in kernel_configs:
        if mode == "forward":
            if permute_x and config.use_tma_load_x:
                continue
        elif mode == "dW":
            if permute_x and config.use_tma_load_x:
                continue
            if permute_y and config.use_tma_load_dy:
                continue
        elif mode == "dX":
            if permute_y and config.use_tma_load_dy:
                continue
        pruned_configs.append(config)
    logging.info(f"After pruning, {len(pruned_configs)} kernel configs")

    return pruned_configs


def power_of_two_range(start, end):
    start = math.log2(start)
    end = math.log2(end)
    return [2**i for i in range(int(start), int(end) + 1)]


def multiples_of_range(
    start,
    end,
    step = 1,
):
    return list(range(start, end + step, step))


def map_key_to_args(key, mode):
    pass


def save_autotune_results(autotune_cache, mode, ref_time, fused_time, results_dir):
    device_name = torch.cuda.get_device_name().replace(" ", "_")
    dt = datetime.datetime.now().strftime("%Y%m%d_%H%M")
    save_dir = f"{results_dir}/{mode}/autotune/{dt}/{device_name}"
    if not os.path.exists(save_dir):
        os.makedirs(save_dir)

    for key, config in autotune_cache.items():
        key = [str(k) if not "torch" in str(k) else str(k.split("torch.")[-1]) for k in key]
        filename = "_".join(key)
        save_path = f"{save_dir}/{filename}.json"
        print(f"Saving autotune results to {save_path}")
        with open(save_path, "w", encoding = "utf-8") as f:
            result = {
                **config.all_kwargs(),
                "ref_time": ref_time,
                "fused_time": fused_time,
            }
            json.dump(result, f)


def get_autotuner(mode):
    if mode == "forward":
        from grouped_gemm.kernels.forward import _autotuned_grouped_gemm_forward_kernel
        return _autotuned_grouped_gemm_forward_kernel
    elif mode == "dW":
        from grouped_gemm.kernels.backward import _autotuned_grouped_gemm_dW_kernel
        return _autotuned_grouped_gemm_dW_kernel
    elif mode == "dX":
        from grouped_gemm.kernels.backward import _autotuned_grouped_gemm_dX_kernel
        return _autotuned_grouped_gemm_dX_kernel
    elif mode == "backward":
        from grouped_gemm.kernels.backward import (
            _autotuned_grouped_gemm_dW_kernel,
            _autotuned_grouped_gemm_dX_kernel,
        )
        return _autotuned_grouped_gemm_dW_kernel, _autotuned_grouped_gemm_dX_kernel
    else:
        raise ValueError(f"Invalid mode: {mode}")


def postprocess_autotune_results(autotuner, mode, ref_time, fused_time, results_dir):
    for key, value in autotuner.cache.items():
        print(f"{mode} {key}: {value.all_kwargs()}")
    save_autotune_results(
        autotuner.cache,
        mode = mode,
        ref_time = ref_time,
        fused_time = fused_time,
        results_dir = results_dir,
    )
